Drying apparatus



W. DREISEL 01mm Arrm'ws Filad Feb.

April 13194 24', 1947 2 Shuts-Sheet 1 //V VE N TOR Will/0m Dreise/ WMJZMJ ATTORNEYS 2 Patented Apr. 13, 1948 UNITED STATES PATENT, OFFICE I I} nnmifizfiauus I I William Drelsel, Lawrence, Mum, assiznor to carnage,-rea r Application Fermi-y 24, 1947, Serial No. 730,423

This invention relates to apparatus for drying.

web material, such for instance as cloth or paper,

" and particularly to drying apparatus in which the web material is held in a slack, non-tensioned condition during the drying operation.

When cloth is bein dried, there is a natural tendency for it to shrink more or less during the drying operation, and as a result, the speed at which a web of cloth is delivered from the drying chamber of a drying apparatus is somewhat less than that at which the wet cloth is fed into the drying chamber.

One of the-objects of the invention is to provide a novel means for supporting the web material to be dried and forwarding it through the drying space of a drying apparatus, which means is so constructed that it will support the web mahaving an elongated drying space through which the Web material is carried and which is divided into a plurality of communicating sections arranged in zigzag fashion one, above the other, together with means to deliver jets of air against both sides of the web material as it is traveling through said connecting dryin space sections, and it is a drying apparatus of this type which i herein illustrated.

In the drawings:

Fig. 1 is a sectional view through a drying apparatus embodying my invention. F iFig. 2 is an enlarged section on theline 2-2,

Fig. 3 is a fragmentary sectional view illustrating the relative arrangement of air nozzles and the supporting rolls and also illustrating a supporting roll of the star type.

Fig. 4 is a side view of'the drying apparatus with the housing member shown in section.

Fig. 5 is a fragmentary view partly in section illustrating the non-positive drive means for the direction rolls.

In the drawings I indicates a. housing element within which is situated the elongated drying space through which the web'material 2 is fed and in which it is dried. This drying space is of the type which comprises a plurality of communicating drying space sections 3, 4, 5, 6, and I which are arranged in zigzag fashion, one above the other. The drying space sections 3 and 4 2 Claims. (Cl. 34-1 59) communicate with each ends as indicated at 8; the drylngspace sections 4 and 5 communicate with each. other at their right-hand ends as shown at 9; the drying space sections 5 and B-communicate with each other at their left-hand ends as shown at III; while the drying space sections 8 and I communicate with each other at their right-hand .ends as shown at II.

The-web material to be dried is fed into the top drying space section 3 at lts'right-hand end in Fig. 1, as shown at 2, and it then travels through the said section I toward the left and passes around a direction roll 40 in space 8, where the two drying space sections 3 and 4 communicate with each other, said direction roll guiding the web into the drying space 4. After the web travels through the drying space 4, it passes around another direction roll 40 which guides it into the drying space 5, said web continuing to pass from one drying space into the next until it I finally emerges from the lower drying spme 1 at its left-hand end,where it passes over a-dlrection pulley II and is .then discharged from th apparatus.

The upper wall I2 '01 each drying space section" is provided with a plurality of downwardly directed nozzles I3 through which air or other drying medium is delivered against the upper side of the web material traveling through said drying space section, and the under wall I4 of each dry-.

ing space section is similarly provided with a plurallty of nozzles I5 which are directed upwardly to deliver air or other drying medium against the under side of the web 2. They air for delivery through these nozzles is supplied from ducts IS,

IT, I-8, I9, 20, 2|, 22, 23, 24 and 25 situated above and below the various drying space sections. The ducts I6, I9, 20, 23, and 24 communicate with a space 26 at the left-hand end of the housing,

which'is equipped with blowers or air-moving elements 21 by which air under pressure is delivered to said ducts. The other ducts I1, I8, 2| and 22 open into a space 28 at the right-hand end of the housing I which is also equipped with blowers or air-moving apparatus 21 by which air under pressure will be forced into said ducts. Each drying space section 3, 4, 5, -6 and I is open at its sides to the interior of the housing I as shown at 50 and the air which is delivered from the nozzles flows over the surface of the web 2 and through the open sides 50 ofthe drying sp ce sections. The blowers or air-moving elements 21 take air from the interior of the housing I and thereby a.

other, at their left-hand assays:

recirculation of air through the space sections is established.

Each drying space'section 3, 4, 5. Land 1 is provided with a pluraliity of supporting rolls 28 that extend across the drying space and on which the web material 2 is supported. 'These supporting rolls are positively driven and preferably with a surface .speed slightly in excess of that at which the web material 2 is moving forward so that the action of the supporting rolls on the web will serve to give it a forward movement, The rolls 29- are supported in bearings 30 which may be secured to the walls of the various ducts on the outside thereof and said rolls may be driven in any desired way. For this purpose each roll is shown as having rigidly mounted on its end a sprocket wheel 3i which is located outside of the drying space, and the said sprocket wheels all have a meshing relation with an endless driving sprocket chain 32 shown in dot and dash lines in Fig. 4. This chain is driven by a suitable motor 33 which is belt connected to a driving sprocket wheel 34 around which the sprocket chain 32 extends. The sprocket chain also passes around direction sprocket wheels 35 situated at the communicating ends of the various drying space sections and loosely mounted on the shafts of the direction rolls 40, and around another direction sprocket wheel 38 loosely mounted on the shaft of a direction roll 42 which guides the web 2 into the drying space section 3. Said sprocket chain 32 also has meshing engagement with another sprocket wheel 51 loosely mounted on the shaft of the direction roll 41. In order to keep the sprocket chain under proper tension, it passes over two additional direction pulleys 21 and forms a loop 38 between said pulleys in which is suspended a suitable tensioning weight 29.

The supporting rolls 29 are thus all operatively connected to the sprocket chain 32 through their sprocket wheels 3| and said rolls are thus positively driven ina direction to feed web material forward.

As stated above, the direction rolls 40 are situated at the communicating ends of adjacent drying space sections, and serve to direct the web material from one drying space section into the next.

In order to insure that there will be no increase in the tension of the web material resulting from shrinkage thereof as it travels through the drying space and around the direction rolls 40,-said rolls 40 are driven through the medium of a non-positive driving means so that the surface speed of each direction roll will be automatically adjusted to the speed at which the'webmaterial is delivered thereto. Hence these rolls will have no tendency to apply to the web material a pulling strain which would increase the tension thereof.

Fig. illustrates one simple form of non-positive driving means adaptable for this purpose.

lliach direction roll 40 is provided with. a shaft extension 43 on which is loosely mounted the corresponding direction sprocket wheel 35' that is and is situated between-a collar-44 that is fast on the shaft extension and another collar 41 that is loose on the shaft extension but is acted upon by a spring 45 that is confined between the collar 41 and a collar 46 that is also fast to the shaft extension but capable of adjustment longitudinally thereof. said collar being held in adjusted position by a set screw 48. The ends of the spring 4! are welded or' otherwise'rigidly secured to the collars 48 and 41.

By adjusting the collar 46 longitudinally of the shaft extension 48 the tension of the spring 45, and hence the spring pressure of the collar 41 against the sprocket wheel 35 will be varied.

. As the sprocket wheel I! is loosely mounted on two collars 44 and 41. Since the. collar 41 is loose on the shaft but rigidly connected to the end of the spring 45, the torque communicated to said collar 41 will be transmitted to the shaft extension through the spring 45 and the collar 48, which is rigidly secured to said shaft extension.

A construction similar to that shown in Fig. 5 is preferably employed in connection with each sprocket wheel 35 and there is therefore provided a yielding frictional drive between each said sprocket wheel 35 and the corresponding direction roll 40, which permits the surface speed of each direction roll to be automatically adjusted to the speed at which the web material is delivdriven by the sprocket chain 32. The sprocket wheel is freeto turn on the shaft extension 42 I end thereto. Hence, if the cloth experiences any shrinkage during its passage through any section of the drying space, the speed of the direction roll 40 at the end of said section by which the web material is directed into the next drying space section will be automatically adjusted to the speed at which the web material is delivered thereto. With this construction each direction roll 40 will tend to have a surface speed slightly more than that at which the web material is delivered thereto. but the frictional drive for each direction roll will prevent any appreciable increase in the tension of the web material due to such shrinkage.

v This invention therefore provides means whereby web material may be carried through an elonated drying space formed in separate communicating sections having a zigzag arrangement while in a slack, non-tension condition, and such slackcondition will prevail throu hout the entire length of the drying spaces, notwithstandin the fact that the cloth my undergo more or less shrinkage while it is being 'dried.

The nozzles l3 which deliver jets of air down wardly against the web material are located directly over the supporting rolls 29, there being one nozzle directly above each supporting roll so that the jet of air which is delivered downwardly by each nozzle impinges against the portion of the web material which is resting on a supporting roll. a

The upwardly directed nozzles I! are situated 60 l between the supporting rolls, each nozzle I! being located between two adjacent rolls, and hence the upwardly directed Jet of air issuing from each nozzle i5 impinges against the under side of the web material 2 at a point between the supporting the portionof the webmaterial between the rolls is raised slightly.

The supporting rolls 29'may be either cylindrical rolls as shown in .Figs. 1 and 2, or may be f5 fluted rolls or star shaped as shown in Fig. 3, or they may have any other desirable cross-sectional shape. The advantage of the star wheel type of roll is that the ribs on the roll have a beating action against the underside of the web material which gives it a slight vibrating movement that helps to maintain the web material in a slack, non-tensioned condition.

I have herein shown means at theinlet endof each ofthe air ducts l6, ll, it, etc., for controlling the air supply thereto and thus controlling the velocity at which the air jets are delivered from the nozzles l3 and i5. One convenient way of accomplishing this is by means of pivoted gates or dampers 58, which are located at the inlet end of the various ducts and which may be adjusted to control the size of the inlet openings of said ducts, and hence the volume of air delivered thereto. 1

This invention is an improvement over the type of dryer using the conventional endless apron for conveying the cloth through the drying space, because with the invention herein the cloth is supported on rotating rolls and there is no danger that the cloth support will leave any marks on the cloth such as might develop where the cloth rests on a traveling apron, but has no appreciable movement relative thereto during its travel from the drying space.

I claim:

1. An apparatus for drying web material while in a slack, non-tensioned condition, comprising means defining an elongated drying space divided into communicating sections having a zigzag arrangement and located one above another. a plurality of web-supporting rolls in each drying space section on which the web material to be dried is loosely supported, a direction roll at the junction of each two connecting drylnl .space sections around which the web material passes and which feeds the web material from one section to the next, means to rotate positively the supporting rolls in each drying space section, thereby to feed the web material forward. a nonpositive driving means for rotating each direction 45 2,226,605

roll whereby the speed thereof automatically adjusts itself to the speed of the-web material being delivered thereto, a plurality of downwardly directed nozzles in each drying space section situated above the web material to direct air jets against the upper face thereof, and a plurality of upwardly directed nomles in each drying space section situated beneath the web material to deliver air jets against the under face thereof, each downwardly directed nozzle being located directly above the supporting roll and each upwardly directed nozzle being situated between two adjacent supporting rolls.

2. An apparatus for drying web material comprising means defining an elongated drying space through which the web material to be dried passes, a plurality of web-supporting rolls within said drying space and on which said web is supported, means to rotate positively said rolls and thereby give the web a forward feeding movement, a plurality of downwardly directed nomles above said rolls to direct air jets against the upper surface of said web, and a plurality of upwardly directed nozzles to direct air Jets against the under side of said web, each downwardly directed nozzle being located directly above oneof the supporting 'rolls and each upwardly directed nozzle being located between two adJacent supporting rolls.

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UNITED mm PATENTS Number Name 7 Date Re. 10,074 Kaiser Apr. 4; 1882 1,469,048 Nelson sept.,26, 1928 1,550,695 Hanson et al. -i- Aug. 25, 1925 2,024,079 whiting Dec. 10, 1985 2,071,016 Andrews Feb. 16, 1087 2,109,233 Williams Apr. 80, 1940 Oifen Dec. 17, 1040 

